T3 deficiency prolongs convulsions induced by acute pentylenetetrazole.
The effects of 3,5,3'-triiodothyronine (T3) levels on threshold, latency and duration of pentylenetetrazole-induced seizures were tested in rats treated with thyroxine (300 micrograms/kg.day, N = 9) or methimazole (60 mg/kg.day, N = 5) dissolved in drinking water. Compared to controls (N = 7), methimazole treatment reduced T3 levels (45.4 +/- 2.0 vs. 33.0 +/- 4.8 ng/dl) and increased seizure duration (36.2 +/- 22.4 vs. 289.6 +/- 24.4 s) and threshold (29.0 +/- vs. 45.5 mg/kg). Thyroxine treatment increased T3 levels (45.4 +/- 2.0 vs. 67.7 +/- 4.8 ng/dl), but had no significant effect on seizures.
Pacheco-Rosado
J
J
Departamento de Fisiología Mauricio Russek, Escuela Nacional de Ciencias Biológicas, IPN, Carpio y Plan de Ayala, México.
Quevedo-Corona
L
L
Zamudio-Hernández
S R
SR
Chambert
G
G
D000818:Animals; D013956:Antithyroid Agents / Q000494:pharmacology; D003106:Colon / Q000503:physiopathology; D003292:Convulsants / Q000008:administration & dosage*; D062787:Drug Overdose; D008297:Male; D008713:Methimazole / Q000494:pharmacology; D010433:Pentylenetetrazole / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000139:chemically induced* / Q000503:physiopathology; D013696:Temperature; D013974:Thyroxine / Q000097:blood / Q000187:drug effects / Q000494:pharmacology; D013997:Time Factors; D014284:Triiodothyronine / Q000097:blood / Q000172:deficiency* / Q000187:drug effects
D013956:Antithyroid Agents; D003292:Convulsants; D014284:Triiodothyronine; D008713:Methimazole; D013974:Thyroxine; D010433:Pentylenetetrazole